Grave

She is regarded as a top-tier Burst 2 buffer in pierce firepower squads.
Her ally attack and pierce buffs are big, but she offers almost no squad healing, so in boss fights the survival slot must be filled by another Nikke.
When Foresight ends, her ammo empties and reloading slows, so she briefly struggles to attack. Also covering Overheat2 means constantly watching normal attack hits and reloads, which takes effort.

Using her Burst triggers Foresight: she takes damage based on current HP every second, but her ammo becomes unlimited and she gains Pierce plus increased Pierce Damage and Increased Critical Rate all at once. All allies get increased attack damage and Pierce Damage, plus Increased Max Ammunition Capacity.
When Foresight ends, she enters Heat Emission1, where her magazine empties and reloading slows. Meanwhile she heals based on her final Max HP, and all allies keep increased Burst Gauge filling speed (the squad fills Burst Gauge faster) and Pierce Damage.
Stacking normal attack hits builds Increased ATK through Overheat2, and reloading after a full magazine removes part of Overheat2. After Foresight triggers, extra hits count, raising Overheat2 stages further and stacking ATK and attack damage increases.

Right after Burst, stack as many normal attack hits as possible during the unlimited-ammo window within the 10 seconds of Foresight.
When Foresight ends, her magazine empties and reloading slows, so set range assuming Heat Emission1 healing and ally buffs.
Leave her on auto by default, and only watch firing density so Overheat2 is not cleared by reloads.

As an Assault Rifle, prioritize the Resilience Cube to raise Reload Speed, and support ammo refills with the Bastion Cube. If Harmony Cube levels differ a lot, use the higher-level cube before the ranking.

Her Burst window adds a big Increased Critical Rate effect, so also cover Critical Damage options. Fill the remaining Overload slots, such as Hit Rate, to suit your engagement range.

Plot SpoilerB opens Foresight and ally buffs at once, so raise her Burst first. Overheat2 holds hit stacking and firepower increases, so raise S2 next. Heat Emission1 holds end-phase healing and ally gauge and pierce buffs, so level S1 too.

In story, bosses, and Tower she can be included as a supporter who raises both Pierce Damage and attack damage buffs. Plan lineups and range including Heat Emission1 after Foresight ends.

Her Burst grants all allies increased attack damage and Pierce Damage, plus Increased Max Ammunition Capacity.
Pierce, unlimited ammo, and Increased Critical Rate stack on herself so she deals damage in the same window.
After Foresight ends, her self-healing and the allies' Burst Gauge filling speed and Pierce Damage increase continue, so the squad fills Burst Gauge faster.

During Foresight, she loses HP every second. When it ends, her magazine empties and reloading slows.
Overheat2 triggers based on normal attack hits and reload conditions.
She provides almost no squad-wide healing, so survival support must come from other slots.